I'm not a seasoned crafter, but I know this skill is extremely useful when crafting high-level recipes. I was planning to participate in the Ishgard restoration with a job that I don't usually use. I gathered/bought the mats I needed, I crafted collectables and upgraded the tools via white scrips, and then I sat down and started crafting. To my horror, I got the huge red error message saying Manipulation wasn't a valid skill name or something. I kid you not, I felt like someone had punched me in the gut and I fell into despair and considered giving up (since I'm a bit late to the party as I was working on a different job at the beginning of rankings). I had to waste so much time rushing through the stupid quests (starting at the level 15 one) to get the damn Manipulation skill.
Now the question plaguing me is: Why the heck is this skill literally the only skill still locked behind the quests? The quests prior to SB are so darn tedious, and the stories are rarely interesting. All the other skills are now ones you get based on your level (correct me if I'm wrong), so why not give Manipulation the same treatment?
EDIT:
Because people don't bother skimming through the discussion which is only 3 pages at the moment of writing this edit, and they immediately jump to the usual "Lazy person who wants everything handed on a plate" conclusion, no. I leveled my crafters fair and square since ARR. I did all the necessary quests back in the day to get the useful cross-skills crafting needed. So please spare me the same hasty and judgemental answers in this thread. If you're not gonna add something useful to the conversation, please move along.